| 摘要 |
PURPOSE:To change a total reflection state into a transmission state and to change optical paths by allowing a triangular prism to contact an optical path which is formed by the total reflection in a polygonal prism and one side of the total reflecting surface of the polygonal prism. CONSTITUTION:Light outputted from an optical fiber 8a is converted by a rod lens 9a into a parallel beam, which travels along the optical path 13 in the total reflection in a parallelogram prism 10 and is converged by a rod lens 9b to enter an optical fiber 8b. When the triangular prism 12 contacts the parallelogram prism 10 and a glass plate 11, the light travels along an optical path 14 and is converged by a rod lens 9c to enter an optical fiber 8c. The triangular prism is brought into contact with the total reflecting surface in the prism to transmit the light and change its optical path, and when the triangular prism contacts another prism, their contacting position is limited to the angle that one side of the prism and a glass plate provided to the prism contain. Consequently, there is no shift in position when the triangular prism contacts the prism and neither unnecessary play nor inclination is caused, thereby eliminating variation in the coupling loss of the light. |
